A variety of imaging approaches are used in different fields. For instance, light field microscopy is an inexpensive, flexible and fast technique for volumetric imaging. A light field microscope (LFM) can be built from any fluorescence microscope by adding an inexpensive microlens array at the intermediate image plane. The lenslet array decomposes incoming light, focusing it onto the image sensor so that light at different field positions and ray angles are recorded by separate sensor pixels. This rich spatio-angular information, captured in a snapshot at a single instant in time, is a discrete representation of the so-called light field where radiance along rays is measured as a function of position and direction in space. Computational processing of a light field micrograph can yield data products of interest to the microscopist, including images with computationally adjustable focal plane and depth of field, or pinhole views from any direction within the microscope's NA that allow one to see behind occluding objects.
Although light field imaging yields great flexibility in post-processing, recording light through the microlens array may result in sacrificing lateral spatial resolution in order to record angular information. For example, while it can be desirable to record many ray angles (e.g., more than 10 in each dimension of the image), the loss of resolution is proportional to the number of discrete ray angles collected. This represents a considerable resolution loss relative to diffraction-limited performance. These and other matters have presented challenges to imaging, for a variety of applications.